Configuring a 4105-MCM-PDPS gateway questions
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dfabian911
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Thursday 10 August 2006 11:18:13 am |
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Configuring a 4105-MCM-PDPS gateway questions
I am attempting to understand how to configure a 4105-MCM-PDPS gateway module and I do not yet have the hardware. I have a few questions:
1) When setting up the MODBUS port commands, if I want to map 5 coils, would I then set up the register count at 5, and lets say I want the coils placed in the internal address register at address 0. Would the 5 coils be placed in bits 0-4 of that internal address word or do I need to allocate one word in the internal database for each coil?
2) In the S7300 hardware config, when I set up the prolinx on the profibus network, what value do I place in the DP Slave Properties-Station parameters-SPC3 User PRM byte? Also what value do I place in the Hex parameter assignment-User_PRM_Data(0) field.?
3) Do I also need to use the sycon software to configure the profibus portion of the gateway?
Thank you- Debbie
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jsanders
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Thursday 10 August 2006 12:01:00 pm |
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RE:Configuring a 4105-MCM-PDPS gateway questions
Debbie,
1.) Coils are binary data and take only one bit; therefore, 16 coils will be held in each ProLinx memory register. Register 0 holds coils 00001-00016, Register 1 holds Coils 00017-00032, etc. Be careful, though, because these same module memory registers can be accessed with Modbus Commands to Read Input Status addresses 10001-10016 & 10017-10032; Input Registers 30001 & 30002; and/or Holding Registers 40001 & 40002.
2.) Those values should be loaded for you from the .GSD file for the module. If you have loaded the .GSD file and are using it in your Step 7 Hardware Configurator software and those parameters are blank, leave them blank.
3.) The SyCon software would only be used to configure a ProLinx module with PDPM (Profibus Master) protocol. SyCon sets up third-party Profibus Slaves in our Profibus Master module. You do not use SyCon to configure our PDPS (Profibus Slave) module. In this case, our module is configured in the Step 7 Hardware Configurator software by loading our .GSD file and assigning Input/Output words and Empty Slots to our slave in that software; which then downloads the configuration to our module.
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dfabian911
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Friday 11 August 2006 5:14:51 am |
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RE:Configuring a 4105-MCM-PDPS gateway questions
Thank you for your quick, informative reply. However, I would like to ask another question. After reading the information I have available to me, I am not sure how exactly I match the Siemens PLC input and output words to the Prolinx modules internal database.
As an example say I have :
2 words of coils in prolinx internal db registers 0-1
4 words of input bits in prolinx internal rdb egisters 2-5
6 4X words in prolinx internal db registers 6-11
5 3X words in prolinx internal db registers 12-16
What registers and how many would the PLC consider Input words, and which and how many would be considered output words?
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jsanders
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Friday 11 August 2006 10:19:02 am |
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RE:Configuring a 4105-MCM-PDPS gateway questions
If you look closely at the ProLinx Profibus Slave Protocol Guide, you will see the Profibus Master will only be able to differentiate Input from Output if you put them in the correct area of the ProLinx module's memory that is assigned for that type of Profibus data. As such, the Modbus address scheme you propose will cause all the data to be seen by the Profibus Master as Input data from ProLinx. It will not be able to write to any of these addresses, as none are in the Output area of ProLinx memory.
Profibus DP is actually a byte-level protocol. It does not make the same distinctions between data types as in the Modbus Protocol. The Profibus Master will see your Modbus addresses as either 34 bytes or 17 words of data, regardless of the fact that the data may be bit-mapped binary data or 16-bit register data.
In the Profibus Protocol guide, you can see that module memory addresses 0-121 are reserved as Profibus Input data...data to go from ProLinx to the Profibus Master. These registers can be addressed in Modbus as Coils 00001-01952 or Holding Registers 40001-40122.
Registers 200-321 are reserved as Profibus Output data...data sent from the Profibus Master to the ProLinx module. These registers can be addressed in Modbus as Coils 03201-5152 or Holding Registers 40201-40322.
The Modbus driver must write to the Profibus Input registers 0-121 in order for the Profibus Master to Read the data; and the Modbus driver must Read from the Profibus Output area, registers 200-321.
And, although you can have up to 122 words of Profibus Input or Output, you must remember that the total Input and Output words cannot exceed 200.
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